> I have discovered that my Zagi Fixx (that's the "park flyer") will soar > and thermals nicely under the right conditions. So, here's my query: w/o > power, the prop on the Zagi still spins as it glides. I asked the good > folks at Zagi about a folding prop and was advised the weight of a folding > prop would be detrimental to performance. Now, the Fixx uses a geared motor > yet the prop still spins during the glide. I seem to recall from my youth, > that some rubber powered planes in those days used a prop which would > "freewheel" after the powered portion of the flight. What this all boils > down to is - should I leave well enough alone or invest in a speed control > with a brake? Is a freewheeling prop a smaller source of drag than a > stopped prop? > A side note: I installed a Dean's whip antenna on the Zagi and, so far > have had no range problems. Might the Deans antenna by an answer for those > carbon fuselages?
Hi Jim, If a prop is truely freewheeling, it will offer less drag than a stopped prop. In the case of a prop attached to the shaft of a motor, when the motor shaft spins, the armature of the motor must also spin. The armature spinning in the magnetic field of the motor magnets is a generator. A force is required to keep the armature spinning; the prop is doing work and this requires the input of energy, energy that is extracted from the air. This creates more drag, which causes the airplane to fly more slowly. A speed control with a brake should stop the prop, but I highly doubt that the increase in performance of your Fixx would merit the expenditure. Regards, Bob Johnson Fond du Lac, WI p.s., There is an indoor electric fly in Columbus, Ohio on October 11 that I am planning on attending. If you can free up that day on your schedule, come on down and help me stir up some air. :) RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
